[Elecraft] K4 TX Antenna port count and usage question

[Paul Gacek]

Hi Wayne

St Kitts is a great destination but no I didn’t get trapped there but instead further south down the coast in Laguna Beach. While St Kitts might have been better, Laguna is more than good enough.

The biggest challenge with my dual KXPX3/KXPA100 is the tom of connecting wires/cables especially when a 2x6 antenna switch and BPFs are included.

This prompts a quick follow up question which apologies ahead of time if it’s a well discussed topic.

Can the second K4 receiver, with appropriate filtering etc listen to a different band continuously while I am calling on another? 

The use case isn’t very sophisticated and is simply searching for mults on one band while calling on another.

I think with the K3s sub receiver that it is disconnected from any antennas while transmitting. 

So the gist of my question is whether the K4 second receiver is disconnected from an antenna when one of the other HF antenna ports is used to transmit.

Paul
W6PNG/M0SNA 
www.nomadic.blog

> On May 15, 2020, at 2:59 PM, Wayne Burdick <n6kr at elecraft.com> wrote:
> 
> Wow, Paul. Between the QTH, food, beer, and your dual KX3-PX3 setup, I'd say you have it made. Of course the K4 will eliminate 90% of the boxes and cables.
> 
> Surely you didn't get trapped down there semi-permanently by Covid-19? Rough life :)
> 
> Wayne
> N6KR
> 
> 
> 
>> On May 15, 2020, at 1:20 PM, Paul Gacek <w6png at yahoo.com> wrote:
>> 
>> Wayne
>> 
>> Thanks for the super quick and succinct reply.
>> 
>> The 3rd TX port is (for me at least) a huge boon and having at least 2 RX opens up a ton of possibilities.
>> 
>> I’m really looking forward to the K4.
>> 
>> Here is a blog post of my continued efforts to find a sweet spot between functionality and portability using two KX3 etc.
>> 
>> https://nomadic.blog/2020/05/08/of-cannons-beer-and-paradise/
>> 
>> Paul
>> W6PNG/M0SNA 
>> www.nomadic.blog
>> 
>>>> On May 15, 2020, at 12:34 PM, Wayne Burdick <n6kr at elecraft.com> wrote:
>>> 
>>> Hi Paul,
>>> 
>>> 
>>>> I think I’ve read that the K4 will have 3 TX antenna ports and possibly up to 5 RX antenna ports.
>>> 
>>> The KAT4 ATU provides three SO-239 antenna jacks. Any of the three antennas can be selected for transmit. By extension, this becomes the default antenna for the receivers, unless you choose a different receive antenna. ATU LC settings for all three antennas are stored on a per-band basis, and each band can have up to 32 different stored segments.
>>> 
>>> There are two receive antenna inputs, RX ANT in 1 and RX ANT in 2.
>>> 
>>> In addition, either of the two KAT4 antennas *not* currently being used for transmit can be used as a receive antenna.
>>> 
>>> In summary, each receiver has access to any of five antennas:
>>> 
>>> - KAT4 ANT 1/2/3, either by sharing the TX antenna or by using one of the KAT4 non-transmit antennas
>>> 
>>> - RX ANT IN 1 and 2
>>> 
>>> For internal transverters, there's a fourth SO-239 (or an N connector). This jack would be shared between two more transverter bands if applicable.
>>> 
>>> 73,
>>> Wayne
>>> N6KR
>>> 
>>> 
>>> 
>